Heatwaves and Wildfires Push a Third of Humanity into Extreme Ozone Pollution, EU Report Finds

Roughly one in three people worldwide breathed dangerously high levels of ground-level ozone during the first eight months of 2026, according to a new European Union analysis that links the surge in toxic air directly to record-breaking heat and a global wave of wildfires. The report, released Wednesday by the EU's Copernicus Climate Atmosphere Monitoring Service (CAMS), found that 34 percent of the global population was exposed to what scientists classify as "extremely poor" ozone air quality between January 1 and September 15. The findings underscore a troubling paradox: even as the world makes headway against some forms of air pollution, ozone remains stubbornly difficult to control, and climate change is making the problem worse.

Ozone pollution forms when heat and sunlight interact with emissions from vehicles, industry and wildfires. The resulting ground-level ozone—distinct from the protective ozone layer high in the atmosphere—is a potent irritant that can scar lung tissue, worsen breathing difficulties, trigger asthma attacks and contribute to a range of other health problems. Because its formation depends on temperature and sunshine, ozone is particularly sensitive to a warming climate, a relationship the CAMS analysis describes as central to this year's alarming figures.

The 2026 results were driven in large part by extreme weather that battered the Northern Hemisphere. Record-shattering heatwaves and enormous wildfires seared parts of Europe and North America, sending plumes of smoke far beyond the regions where they originated. Indonesia also experienced major fires, and the El Nino weather pattern—which began in June and is expected to peak later this year—could stoke additional blazes across Southeast Asia, the report warns. Smoke from these fires does not stay put; it can travel thousands of kilometres, crossing continents and oceans.

"Air pollution does not stop at borders," said Laurence Rouil, director of CAMS, speaking at the launch of the Atmosphere Watch report. "It can travel thousands of kilometres, crossing continents and oceans and affecting air quality far from its source." Her remarks highlight a fundamental challenge in global air-quality management: the pollutants that harm people in one country are often produced in another, making unilateral action insufficient.

The scale of the exposure is stark. Beyond the 34 percent of the world's population living with "extremely poor" ozone levels, a further 17 percent breathed "very poor" air, while just five percent enjoyed "good" ozone conditions. The CAMS assessment uses satellite data and computer models to track both pollution and fire activity, and it measures ozone concentrations against the World Health Organization's exposure guidance, which sets 100 micrograms per cubic metre as the maximum recommended eight-hour average.

Asia bears the heaviest burden. More than half of the continent's population—53 percent—was exposed to "extremely poor" ozone air, with another 22 percent breathing "very poor" air. The report attributes the region's high levels to a combination of industrialisation, economic development and transport emissions, compounded by wildfires and the widespread burning of agricultural residue. Among the cities recording "extremely poor" ozone levels were New Delhi, Dhaka, the Chinese megalopolis Chongqing and Lahore in Pakistan, all of which are already grappling with some of the world's worst air quality.

The picture is also grim across much of the developed world. Two-thirds of North America's population and 45 percent of Europe's were exposed to "poor" or "very poor" air quality, according to the analysis. In North America, ozone levels have remained "relatively unchanged" despite ambitious emissions-reduction policies, suggesting that existing regulations have not been enough to counteract the influence of a warming climate and increasingly frequent fires. In Europe, EU regulation has proven effective at cutting most harmful air pollutants—but ozone stands out as the exception. Ian Marnane, an official at the European Environment Agency, told a media briefing that ozone pollution is linked to 60,000 premature deaths annually across the continent.

Africa's air-quality challenges stem from a different mix of sources. Smoke from forest fires, crop burning and household cooking are significant contributors to the continent's pollution, while Saharan dust is swept as far north as Europe. Eight percent of Africa's population endured "extremely poor" air quality this year, and conditions were "very poor" or "poor" for a further 19 percent of the continent's residents.

In South America, ozone concentrations were very high in Sao Paulo and extremely elevated in Rio de Janeiro, though overall air quality was "good" or "fair" for 81 percent of the region's population. The one genuine bright spot in the global assessment was Oceania, including Australia and New Zealand, where two-thirds of residents enjoyed "good" ozone levels and the remaining third lived under "fair" conditions.

The report's broader message is that progress on air pollution is uneven and vulnerable to reversal. Decades of effort have reduced emissions of many harmful substances, yet ozone has resisted those gains because its formation is so tightly bound to heat and sunlight—two factors that climate change is intensifying. As heatwaves grow more frequent and severe, and as wildfires become larger and more widespread, the conditions that produce dangerous ozone are likely to recur, if not worsen. For policymakers, the findings suggest that conventional pollution controls alone will not be enough; tackling ozone will require addressing its climate drivers as well. And because polluted air ignores national boundaries, the report makes clear that the problem demands coordinated international action rather than isolated national remedies. With the El Nino pattern still building toward its peak, the coming months could bring further deterioration in regions already struggling to protect their populations from the air they breathe.